add avprogram_id to streams_changed() callback

This is an int to match type with AVProgram.  In mpegts.c, SectionHeader::id is
a uint16_t as ISO/IEC 13818-1:2021 specifies for program_number.

This allows us to ignore stream changes in programs that are not being watched
when there is more than one program.

Regarding the changes to mpeg.c:
Originally from:
dvb/ac3 patches 1, 2, and 3 from Mark Anderson
87795f6

changed in:
Refs #8134. internal dvd player. resolve problem where pcm_s16be audi…
e64371a

change reverted in:
Refs #8134. revert most of [24239]. Anduin withers reported it makes …
a3d6e14

referencing: #8134 (internal dvd player: pcm_s16be improperly detected as pcm_dvd audio codec.) – MythTV
https://code.mythtv.org/trac/ticket/8134

An MPEG Program Stream can only have one program, so FFmpeg does not create an
AVProgram for it.  Thus av_find_program_from_stream() (and therefore
get_current_AVProgram()) will always return nullptr, so avprogram_id will be
ignored.

The calling conventions of functions with "C" and "C++" language linkage are not
necessarily the same; however, in practice they are, so
AvFormatDecoder::streams_changed() could be used directly.  Doing it correctly
still eliminates the use of a friend function and its double declaration at only
the cost of an extra function call, which doesn't matter since streams_changed()
is only called very rarely.

mythtv/external/FFmpeg/libavformat/avformat.h

@@ -1340,7 +1340,7 @@ typedef struct AVFormatContext {
 
     /* Myth addons */
     /* mpeg-ts support */
-    void (*streams_changed)(void*);
+    void (*streams_changed)(void* stream_change_data, int avprogram_id);
     void *stream_change_data;
     /* End Myth addons */
 

mythtv/external/FFmpeg/libavformat/mpeg.c

@@ -638,7 +638,7 @@ static int mpegps_read_packet(AVFormatContext *s,
 
     /* notify the callback of the change in streams */
     if (s->streams_changed) {
-        s->streams_changed(s->stream_change_data);
+        s->streams_changed(s->stream_change_data, -1);
     }
 
 found:

mythtv/external/FFmpeg/libavformat/mpegts-mythtv.c

@@ -2750,7 +2750,7 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
         !is_pmt_equal(prg, &old_program))
     {
         av_log(ts->stream, AV_LOG_DEBUG, "streams_changed()\n");
-        ts->stream->streams_changed(ts->stream->stream_change_data);
+        ts->stream->streams_changed(ts->stream->stream_change_data, h->id);
     }
     // end MythTV
 

mythtv/libs/libmythtv/decoders/avformatdecoder.cpp

@@ -883,19 +883,32 @@ void AvFormatDecoder::InitByteContext(bool forceseek)
         .arg(buf_size).arg(streamed).arg(m_ic->pb->seekable).arg(m_ringBuffer->GetReadBufAvail()));
 }
 
-extern "C" void HandleStreamChange(void *data)
+void AvFormatDecoder::streams_changed(void *data, int avprogram_id)
 {
     auto *decoder = reinterpret_cast<AvFormatDecoder*>(data);
 
     int cnt = decoder->m_ic->nb_streams;
 
     LOG(VB_PLAYBACK, LOG_INFO, LOC +
-        QString("streams_changed 0x%1 -- stream count %2")
-            .arg((uint64_t)data,0,16).arg(cnt));
+        QString("streams_changed 0x%1 -- program_number %2 stream count %3")
+            .arg((uint64_t)data,0,16).arg(QString::number(avprogram_id), QString::number(cnt)));
 
+    auto* program = decoder->get_current_AVProgram();
+    if (program != nullptr && program->id != avprogram_id)
+    {
+        return;
+    }
     decoder->m_streamsChanged = true;
 }
 
+extern "C"
+{
+    static void HandleStreamChange(void *data, int avprogram_id)
+    {
+        AvFormatDecoder::streams_changed(data, avprogram_id);
+    }
+}
+
 int AvFormatDecoder::FindStreamInfo(void)
 {
     m_avCodecLock.lock();

mythtv/libs/libmythtv/decoders/avformatdecoder.h

@@ -36,8 +36,6 @@ class MythSqlDatabase;
 
 struct SwsContext;
 
-extern "C" void HandleStreamChange(void *data);
-
 class AudioInfo
 {
   public:
@@ -81,8 +79,6 @@ class AudioInfo
 /// A decoder for media files.
 class AvFormatDecoder : public DecoderBase
 {
-    friend void HandleStreamChange(void *data);
-
   public:
     AvFormatDecoder(MythPlayer *parent, const ProgramInfo &pginfo,
                     PlayerFlags flags);
@@ -178,6 +174,8 @@ class AvFormatDecoder : public DecoderBase
 
     static int GetMaxReferenceFrames(AVCodecContext *Context);
 
+    static void streams_changed(void *data, int avprogram_id);
+
   protected:
     int  AutoSelectTrack(uint type) override; // DecoderBase
     void ScanATSCCaptionStreams(int av_index);